Unfortunately there is no quick fix. Anything other than doing it right may result in a temporary solution but eventually the problem will come back. If you are talking about a teak deck on your flying bidge---- teak planks over a subdeck of a fiberglass-pywood-fiberglass sandwich--- then there could be a variety of problems causing water ingress.
If you are talking about some other water ingress that has nothing to do with the flying bridge deck itself, then I have misinterpreted your question.* But if you are talking about the deck.......
To start with, if the teak plank seams really are caulked with 5200, that is about the worst material possible to caulk a deck with. Deck caulking is purpose-built stuff, the best being TDS. Other seam materials that are used include Lifecaulk (near worthless in our experience) and Thiokol, which was the sealant material used in the past by a lot of manufacturers but has long since been superseded by TDS.
If the seams have started to pull away from one side or the other of the groove--- and you may have to get down real close and pry lightly
with a knife to see this--- water can get under the planks and from there migrate down into the subdeck and even-- if the plank screws penetrate through the bottom of the subdeck-- into the cabin below.
The cure is to reef out all the existing seam material--- which will be bear if it really is 5200 (use a heat gun to soften the 5200 for removal)--- and recaulk the seams using the proper process, which includes the installation of bond-breaker tape in the bottoms of the grooves, and proper materials.* Like I said, TDS is the absolute best stuff on the market for this.
Another way moisture can get under the teak is if there are missing plugs over the recessed screws that hold the teak planks down.* While not as likely to admit water as seam sealant that has pulled free of a groove, moisture can migrate down past exposed screws into the subdeck.* The cure there is to remove the screw, rebore and re-countersink the hole using the appropriate tool, replace the screw with a bit of sealant on the tip (the one thing I've found Lifecaulk to be good for), and install a new plug.
The edge of the teak deck on a flying bridge can also be a way moisture can get in if it is not sealed up properly to the fiberglass under or beside it.
Also, depending on the age of the boat and the use it has gotten, it's possible that the teak deck planks have been worn (or worse, sanded) down to the point where the bottom of the grooves between the planks are almost even with the upper surfaces of the planks. This occurs when an owner is bound and determined to keep the teak decks on his boat "teak colored."* This is one of the absolute worst things one can do to a teak deck.* Sanding or using the so-called teak cleaners and restorers which do exactly the same thing as sanding only they do it chemically, removes the upper wood cells to expose the brown cells underneath.* These cells of course immediatly start to weather gray (unless the boat is in a dark boathouse or the deck is covered in some way) and in a while the owner does the sanding or chemical restoring again.* And wood that goes away does not come back.* The end result is a continual thinning of the planks.
If you don't like naturally silver-gray teak on your deck and you can't keep the boat in a nice, dark boathouse, you've got the wrong boat.
Over-sanded planks and nearly gone grooves in places was what our main deck was like when we bought our boat 13+ years ago.* Even though the sealant looked okay at first glance, on inspection it was just a thin strip and was doing little to prevent moisture from getting down between the planks.* The cure here is to reef out all the existing sealant, regroove the deck planks so the grooves are the proper depth, then prep the grooves correctly, install bond-breaker tape, and reseam them.* This is what we did some 11 years ago.
If you have rot in the subdeck, there is no really long-term effective cure other than to remove the planking, cut out the rot, replace with new material, and replace the decking properly.* The rot will not "go away" on its own, and any attempt at a quick sealing job over the teak planks will eventually fail and moisture will start getting in again.
If you are not willing or able to do a rot removal-new material job, at the very least the teak deck should be re-seamed with the right material (if it really is
5200-- I can't believe that anyone other than a totally ignorant bozo would use this stuff as a seam sealant).* Or if you find* the deck is seamed with a proper material, a replacement of all the seams that are pulling free as well as a minute inspection of the edges of the deck to make sure they are properly sealed.
You will most likely get all sorts of suggestions of quick fixes.* Some of them will probably work for a little while.* But the reality is that if you want to effect a long-lasting cure, the only way to do that is to do it right.
I learned everything I know about the care and feeding from a couple of career shipwrights in Bellingham plus several extremely experienced people, including a former yard owner who specialized in the repair, mainenance, and upgrading of Grand Banks boats, wood and glass, on the Grand Banks owners forum.* There is a ton of information about the proper way to repair, maintain, and care for a teak deck (and the subdeck underneath it) in the archives of that forum http://www.grandbanksowners.com/
because almost every GB made started out with a high quality teak deck.* The deck s a major part of the character of the boat, so most owners are very interested in maintaining and repairing them properly when the need arises.
-- Edited by Marin on Wednesday 22nd of February 2012 02:15:03 PM